Nematodes
Nematodes are small, usually microscopic worm like animals. Nematodes are among the most abundant animals on Earth. They occur as parasites in animals and plants or as free-living forms in soil, fresh water, and marine environments. Plant parasitic nematodes cause substantial damage to agricultural industries annually with the most damaging being root knot nematodes and soybean cyst nematodes.
TDA can test soil and plant material for nematodes with a fee of $25 per sample. Please contact the state plant pathologist for more information.
Root-knot nematodes are plant-parasitic nematodes from the genus Meloidogyne. They exist in soil in areas with hot climates or short winters. About 2000 plants worldwide are susceptible to infection by root-knot nematodes and they cause approximately 5% of global crop loss. Root-knot nematode symptoms on plant roots are dramatic. As a result of nematode feeding, large galls or "knots" can form throughout the root system of infected plants. Severe infections result in reduced yields on numerous crops and can also affect consumer acceptance of many plants, including vegetables.
Read More:
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7489.html
https://www.apsnet.org/edcenter/disandpath/nematode/pdlessons/Pages/RootknotNematode.aspx
Pine wood Nematode is a North American native microscopic wormlike creature causing Pine wilt disease. The nematode is vectored by pine sawyer beetles while feeding on the trees. Pine wood nematode is regulated throughout the United States by countries like Japan and China which import large quantities of conifer wood.
Read More:
https://www.fs.usda.gov/naspf/sites/default/files/pinewilt.pdf
Soybean Cyst Nematode is a devastating pest to soybeans and other legumes. These nematodes begin feeding on the roots and work into the vascular system of the plant. Dead female nematodes become egg filled cysts which hatch and begin feeding on the plants.
Symptoms include yellowing and stunting when populations are high. Weakening or stress plants are more susceptible to other pathogens. Soybean cyst nematode is the most yield limiting disease of soybean in the U.S.
Read More:
https://extension.umn.edu/soybean-pest-management/soybean-cyst-nematode-management-guide
https://www.invasivespeciesinfo.gov/terrestrial/invertebrates/soybean-cyst-nematode